How can I get a comma separated list of firstnames?

Question

This is my list of addresses in a YAML file :

addresses:
  person1:
    firstname: Maria
    lastname:  Smith
  person2:
    firstname: July
    lastname:  Weber
  person3:
    firstname: John
    lastname:  Kurt
  person4:
    firstname: Simon
    lastname:  Gates

What i need is a comma separated string like Maria, July, John, Simon

I tried the following:

firstnames: >-
  {% set lastnames_list= [] %}
  {% for name in addresses %}
      {{ name.firstname | join(",")}}
  {% endfor %}
  {{ lastnames_list }} 

firstnames: >-
  {% set lastnames_list= [] %}
  {% for name in addresses %}
      {{ name | map(attribute="firstname") | join(",") }}
  {% endfor %}
  {{ lastnames_list }} 

firstnames: '{{ addresses | map(attribute="firstname") | join(",") }}'

But Ansible gives the following output:

The task includes an option with an undefined variable. The error was: 'unicode object' has no attribute 'firstname'

score 3 · Accepted Answer · answered Jun 21 '20 at 10:44

3

Simple json_query filter can be used to achieve the result.

- debug:
    msg: '{{ addresses | json_query("@.*.firstname") | join(", ") }}'

gives

ok: [localhost] => 
  msg: Maria, July, John, Simon

answered Jun 21 '20 at 10:44

Moon

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β.εηοιτ.βε · Answer 2 · 2020-06-21T10:47:49.717

The map filter actually applies a filter on a sequence of objects or looks up an attribute.

But here, you do have a dictionary, not a sequence of objects nor an object with attributes only.

In order to achieve what you are looking for there is two path:

If you stick with your actual YAML structure, you can turn your dict back in a normalized list using Ansible dict2items filter:
```
firstnames: "{{ addresses | dict2items | map(attribute='value') | map(attribute='firstname') | join(',') }}"
```

You can switch your dictionary into a list, changing the structure of your list of addresses this way, and then your Jinja will work:

addresses:
  - firstname: Maria
    lastname:  Smith
  - firstname: July
    lastname:  Weber
  - firstname: John
    lastname:  Kurt
  - firstname: Simon
    lastname:  Gates

Will work with

firstnames: "{{ addresses | map(attribute='firstname') | join(',') }}"

Here are the working examples and their corresponding recap.

Playbook using dict2items:

- hosts: local
  gather_facts: no
  vars:
    addresses:
      person1:
        firstname: Maria
        lastname:  Smith
      person2:
        firstname: July
        lastname:  Weber
      person3:
        firstname: John
        lastname:  Kurt
      person4:
        firstname: Simon
        lastname:  Gates

  tasks:
    - debug:
        msg: "{{ addresses | dict2items | map(attribute='value') | map(attribute='firstname') | join(',') }}"

Gives the recap:

PLAY [local]    **************************************************************************************************************

TASK [debug]    **************************************************************************************************************
ok: [local] => {
    "msg": "Maria,July,John,Simon"
}

PLAY RECAP    ****************************************************************************************************************
local                      : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Playbook changing the YAML address structure:

- hosts: local
  gather_facts: no
  vars:
    addresses:
      - firstname: Maria
        lastname:  Smith
      - firstname: July
        lastname:  Weber
      - firstname: John
        lastname:  Kurt
      - firstname: Simon
        lastname:  Gates

  tasks:
    - debug:
        msg: "{{ addresses | map(attribute='firstname') | join(',') }}"

Gives the recap:

PLAY [local]    **************************************************************************************************************

TASK [debug]    **************************************************************************************************************
ok: [local] => {
    "msg": "Maria,July,John,Simon"
}

PLAY RECAP    ****************************************************************************************************************
local                      : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Tanks a lot for your reply. I consider changing to a list but the dictionary is used in other places in the playbook.... — ducato66, Jun 21 '20 at 12:08

How can I get a comma separated list of firstnames?

2 Answers2